openHAB - One Wire Bricklet

This is the description of the openHAB API bindings for the One Wire Bricklet. General information and technical specifications for the One Wire Bricklet are summarized in its hardware description.

An installation guide for the openHAB API bindings is part of their general description.

Examples

The example code below is Public Domain (CC0 1.0).

Read DS 18B 20Temperature

Download (ExampleReadDS18B20Temperature.rules)

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rule "Read DS18B20 Temperature"
when
    System started // Replace with trigger of your choice
then
    // Change XYZ to the UID of your One Wire Bricklet
    val owActions = getActions("tinkerforge", "tinkerforge:brickletonewire:XYZ")

    owActions.brickletOneWireWriteCommand(0, 78) // WRITE SCRATCHPAD
    owActions.brickletOneWireWrite(0) // ALARM H (unused)
    owActions.brickletOneWireWrite(0) // ALARM L (unused)
    owActions.brickletOneWireWrite(127) // CONFIGURATION: 12-bit mode

    owActions.brickletOneWireWriteCommand(0, 68) // CONVERT T (start temperature conversion)

    createTimer(now.plusSeconds(1), [| // Wait for conversion to finish

        owActions.brickletOneWireWriteCommand(0, 190) // READ SCRATCHPAD

        val tLow = owActions.brickletOneWireRead().get("data") as int
        val tHigh = owActions.brickletOneWireRead().get("data") as int

        var float temperature = tLow + (tHigh * 256)

        // Negative 12-bit values are sign-extended to 16-bit two's complement
        if (temperature > 4096) {
            temperature = temperature - 65536
        }

        // 12-bit mode measures in units of 1/16°C
        logInfo("Example", "Temperature: " + temperature / 16.0 + "°C")
    ])
end

Thing

UID:
  • tinkerforge:brickletonewire:[UID]
Required firmware version:
  • 2.0.0
Firmware update supported:
  • yes
Channels:
    Actions:
    Parameters:
    • Communication LED Config – Type: Choice, Default: Show Communication
    • The communication LED configuration. By default the LED shows 1-wire communication traffic by flickering. You can also turn the LED permanently on/off or show a heartbeat.
    • Options: Off, On, Show Heartbeat, Show Communication

    • Status LED Config – Type: Choice, Default: Show Status
    • The status LED configuration. By default the LED shows communication traffic between Brick and Bricklet, it flickers once for every 10 received data packets. You can also turn the LED permanently on/off or show a heartbeat. If the Bricklet is in bootloader mode, the LED is will show heartbeat by default.
    • Options: Off, On, Show Heartbeat, Show Status

    Channels

    Actions

    Actions can be used in rules by creating an action object. All actions return a Map<String, Object>. Returned values can be accessed by name, sometimes the type deduction needs some hints, as shown below:

    val actions = getActions("tinkerforge", "tinkerforge:brickletonewire:[UID]")
    val hwVersion = actions.brickletOneWireGetIdentity().get("hardwareVersion") as short[]
    logInfo("Example", "Hardware version: " + hwVersion.get(0) + "." + hwVersion.get(1) + "." + hwVersion.get(2))
    

    Basic Actions

    brickletOneWireSearchBus()
    Return Map:
    • identifier – Type: long[], Length: variable, Range: [0 to 264 - 1]
    • status – Type: int, Range: See constants

    Returns a list of up to 64 identifiers of the connected 1-Wire devices. Each identifier is 64-bit and consists of 8-bit family code, 48-bit ID and 8-bit CRC.

    To get these identifiers the Bricklet runs the SEARCH ROM algorithm, as defined by Maxim.

    The following constants are available for this function:

    For status:

    • val STATUS_OK = 0
    • val STATUS_BUSY = 1
    • val STATUS_NO_PRESENCE = 2
    • val STATUS_TIMEOUT = 3
    • val STATUS_ERROR = 4
    brickletOneWireResetBus()
    Return Map:
    • status – Type: int, Range: See constants

    Resets the bus with the 1-Wire reset operation.

    The following constants are available for this function:

    For status:

    • val STATUS_OK = 0
    • val STATUS_BUSY = 1
    • val STATUS_NO_PRESENCE = 2
    • val STATUS_TIMEOUT = 3
    • val STATUS_ERROR = 4
    brickletOneWireWrite(int data)
    Parameters:
    • data – Type: int, Range: [0 to 255]
    Return Map:
    • status – Type: int, Range: See constants

    Writes a byte of data to the 1-Wire bus.

    The following constants are available for this function:

    For status:

    • val STATUS_OK = 0
    • val STATUS_BUSY = 1
    • val STATUS_NO_PRESENCE = 2
    • val STATUS_TIMEOUT = 3
    • val STATUS_ERROR = 4
    brickletOneWireRead()
    Return Map:
    • data – Type: int, Range: [0 to 255]
    • status – Type: int, Range: See constants

    Reads a byte of data from the 1-Wire bus.

    The following constants are available for this function:

    For status:

    • val STATUS_OK = 0
    • val STATUS_BUSY = 1
    • val STATUS_NO_PRESENCE = 2
    • val STATUS_TIMEOUT = 3
    • val STATUS_ERROR = 4
    brickletOneWireWriteCommand(long identifier, int command)
    Parameters:
    • identifier – Type: long, Range: [0 to 264 - 1]
    • command – Type: int, Range: [0 to 255]
    Return Map:
    • status – Type: int, Range: See constants

    Writes a command to the 1-Wire device with the given identifier. You can obtain the identifier by calling SearchBus(). The MATCH ROM operation is used to write the command.

    If you only have one device connected or want to broadcast to all devices you can set the identifier to 0. In this case the SKIP ROM operation is used to write the command.

    The following constants are available for this function:

    For status:

    • val STATUS_OK = 0
    • val STATUS_BUSY = 1
    • val STATUS_NO_PRESENCE = 2
    • val STATUS_TIMEOUT = 3
    • val STATUS_ERROR = 4

    Advanced Actions

    brickletOneWireGetCommunicationLEDConfig()
    Return Map:
    • config – Type: int, Range: See constants, Default: 3

    Returns the configuration as set by the thing configuration

    The following constants are available for this function:

    For config:

    • val COMMUNICATION_LED_CONFIG_OFF = 0
    • val COMMUNICATION_LED_CONFIG_ON = 1
    • val COMMUNICATION_LED_CONFIG_SHOW_HEARTBEAT = 2
    • val COMMUNICATION_LED_CONFIG_SHOW_COMMUNICATION = 3
    brickletOneWireGetChipTemperature()
    Return Map:
    • temperature – Type: int, Unit: 1 °C, Range: [-215 to 215 - 1]

    Returns the temperature as measured inside the microcontroller. The value returned is not the ambient temperature!

    The temperature is only proportional to the real temperature and it has bad accuracy. Practically it is only useful as an indicator for temperature changes.

    brickletOneWireGetStatusLEDConfig()
    Return Map:
    • config – Type: int, Range: See constants, Default: 3

    Returns the configuration as set by the thing configuration

    The following constants are available for this function:

    For config:

    • val STATUS_LED_CONFIG_OFF = 0
    • val STATUS_LED_CONFIG_ON = 1
    • val STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
    • val STATUS_LED_CONFIG_SHOW_STATUS = 3
    brickletOneWireGetSPITFPErrorCount()
    Return Map:
    • errorCountAckChecksum – Type: long, Range: [0 to 232 - 1]
    • errorCountMessageChecksum – Type: long, Range: [0 to 232 - 1]
    • errorCountFrame – Type: long, Range: [0 to 232 - 1]
    • errorCountOverflow – Type: long, Range: [0 to 232 - 1]

    Returns the error count for the communication between Brick and Bricklet.

    The errors are divided into

    • ACK checksum errors,
    • message checksum errors,
    • framing errors and
    • overflow errors.

    The errors counts are for errors that occur on the Bricklet side. All Bricks have a similar function that returns the errors on the Brick side.

    brickletOneWireGetIdentity()
    Return Map:
    • uid – Type: String, Length: up to 8
    • connectedUid – Type: String, Length: up to 8
    • position – Type: char, Range: ['a' to 'h', 'i', 'z']
    • hardwareVersion – Type: short[], Length: 3
      • 0: major – Type: short, Range: [0 to 255]
      • 1: minor – Type: short, Range: [0 to 255]
      • 2: revision – Type: short, Range: [0 to 255]
    • firmwareVersion – Type: short[], Length: 3
      • 0: major – Type: short, Range: [0 to 255]
      • 1: minor – Type: short, Range: [0 to 255]
      • 2: revision – Type: short, Range: [0 to 255]
    • deviceIdentifier – Type: int, Range: [0 to 216 - 1]

    Returns the UID, the UID where the Bricklet is connected to, the position, the hardware and firmware version as well as the device identifier.

    The position can be 'a', 'b', 'c', 'd', 'e', 'f', 'g' or 'h' (Bricklet Port). The Raspberry Pi HAT (Zero) Brick is always at position 'i' and the Bricklet connected to an Isolator Bricklet is always as position 'z'.

    The device identifier numbers can be found here

    Internal Actions

    brickletOneWireReadUID()
    Return Map:
    • uid – Type: long, Range: [0 to 232 - 1]

    Returns the current UID as an integer. Encode as Base58 to get the usual string version.